The invention relates to removing non-text information from a color image.
It is not uncommon for extraneous marks to appear on a page containing text information. Such marks include stains (e.g., stains resulting from spills or aging of the paper), background marks (e.g., a color background or faint background image), and marks made by a user (e.g., those made by highlighting pens).
These extraneous marks may interfere with clear reproductions of the page because of difficulty in distinguishing text and non-text data. For example, if a contrast-based black and white copier is used to reproduce the page of text, the extraneous marks on the page may not have a sufficient contrast to the text, which may result in a blending of the marks with the text from the copying. The same difficulty may also be experienced when a color or black and white scanning device is used to convert the page for storage and processing in a computer system which is to be later printed on a black and white printer.